Variable speed control for stock quotation projectors



Jan. 23, 1934. z N 1,944,173

VARIABLE SPEED CONTROL FOR STOCK QUOTATION PROJECTORS Original Filed April 23, 1929 M ATTORN EY Patented Jan. 23, 1934 PATENT OFFICE VARIABLE SPEED CONTROL FOR STOCK QUOTATION PROJECTORS August D. Eitzen, Rockville Center, N. Y., as-

signor to News Projection Corporation, New York, N. Y., a corporation of New York Application April 23, 1929, Serial No. 357,449 Renewed January 21, 1933 16 Claims.

My present invention relates generally to stock ticker projecting machines, and has particular reference to the automatic control of the speed of operation thereof.

It is well known that a stock ticker, adapted to discharge marked tape, functions periodically or intermittently depending upon the variable transactions which it records. Where a tape of this character is passed through a projecting device, so that the markings thereon may be cast upon a suitable screen or screens, it has frequently been the custom to provide a tape-rewinding mechanism which draws the tape through the projecting device as long as the'ticker discharges the same, and ceases to draw the tape whenever the ticker ceases to operate. With tickers which operate at relatively great speeds, a constant transmission of tape through the projecting device at a corresponding speed, interrupted by periods of rest of the tape, is somewhat objectionable because of the strain upon the eyes of the observers. It is far preferable to draw the tape through the projecting device at varying rates of speed conforming to the rates at which the ticker is operating so that periods of absolute rest occur only at those times when the ticker has ceased to function for a sustained period of time.

A general object of my invention is to provide a projection machine of the latter character, and more particularly, one wherein the tape-drawing or rewinding mechanism is operated automatically in a simple and eflicient manner at varying rates of speed dependent upon the output of the ticker.

A more particular object of my invention is to provide a construction which employs an electric motor and which resorts to the control of speed of the motor by means of a rheostat, the present construction, however, being devoid of frictionally-made electric contacts. I have found that by the employment of a rheostat with a series of contacts over which a complementary contact travels and makes frictional engagement, difficulties are encountered by virtue of the wear and tear upon the contacts, the constant exposure thereof, and the problems of sparking which arise. In accordance with my present invention, a plurality of contacts are employed, but frictional engagement is entirely dispensed with.

Briefly, my invention makes use of a conductive liquid such as mercury, and a particular feature of my construction resides in the provision of a stationary well or reservoir with which a set of rheostat contacts are associated.

It is a particular feature of my invention to provide a construction which involves only one moving part, this part being a pivoted member. All the advantages of automatic and variable speed control, and of the employment of a liquid such as mercury for purposes of contact making, are achieved by my present construction, despite the fact, as mentioned, that only a single element is subject to movement.

The stationary well which I employ is substantially U-shaped and I provide a supply of conductive liquid therein normally at a relatively low level. A set of contacts are arranged in association with the well, and the method of bringing the liquid into predetermined association with these contacts relies upon the principles of liquid displacement, a displacement member being so constructed and arranged as to enter the liquid and cause a change in level thereof, accordingly.

Another object of my invention is to provide an automatic rheostat device of the foregoing character wherein all sparking whatsoever is prevented. I accomplish this by means of a nonconductive liquid suitably associated with the conductive liquid so as to quench any sparks which would otherwise be induced.

A general object of my invention is to provide a construction which is extremely simple, compact, inexpensive to manufacture, easy to install, and eflicient and reliable in operation.

'From another aspect, my invention relates to the provision of an improved electrical switch, since a number of the features of my present con-- struction are not limited to employment with stock ticker projecting machines, but will have a far wider applicability.

For the attainment of the foregoing objects and such other objects as may hereinafter appear or be pointed out, I have constructed a device embodying the features of my invention and illustrated in the accompanying drawing wherein Figure l is an elevational view, mainly diagrammatic, showing a stock ticker projecting machine provided with my improvement;

Figure 2 is an enlarged elevational view. partly in section, illustrating the details of my improved switch, and showing the electrical connections diagrammatically; and

Figure 3 is a plan view of Figure 2, all electrical leads having been omitted for the sake of clearness.

In Figure l I have shown a stock ticker 10 which is adapted to discharge a marked tape 11, the latter entering and passing through a suitable projecting device 12 and being'thereupon directed toward a rewinding or tape-drawing mechanism 13. Within the projecting device 12 is a source of light and other suitable mechanism for projecting a beam of light upwardly through the marked tape and through a suitable objective 14 or the like, thence onto a. screen. The interior mechanism of the projecting device 12 has not been shown. The rewinding mechanism designated by the reference numeral 13 in Figure 1 includes an electric motor which has not been shown in this figure but which is diagrammatically represented in Figure 2 by the reference numeral 15. This motor has an armature l6 and a field 17.

Between the stock ticker 10 and the projecting device 12 I provide the apparatus hereinafter to be more fully described, and in the illustrated embodiment I have shown this apparatus attached to a side of the projecting device 12 as by means of a bracket 18. It consists of a well 19 which is substantially U-shaped in that it embodies two upwardly extending arms. As viewed in Figure 2, the left arm 20 conforms to an arcuate portion of a torus ring. The extent of this are is approximately 90, as illustrated. The other arm of the well 21 is substantially straight, of smaller bore than the arm 20 and inclined upwardly at a slight angle (shown at approximately 30) to the horizontal. In the illustrated embodiment, the entire well is constructed of insulating material such as bakelite, hard rubber, or the like, although it will be obvious after this specification has been read that the well itself need not necessarily be of insulating material.

Mounted in association with the arm 21 so as to project into the interior of the latter are a set of electrical contacts. One contact 22 is positioned at the lower end of the arm 21 and is electrically connected as by means of a lead 23 to one side of the line or current source. The other contacts constitute a group and are all electrically connected through a rheostat or resistance 24 to the armature in which circuit this switch element has been intercepted. More particularly, it is to be noted that the field winding 17 is arranged in parallel with the armature 16, in the case of a shunt motor, as shown in the drawing. While the field remains on the line, its current does not pass through the switch. It is of course understood that the present invention will work equally as well with a series motor -or any variable speed type motor. A lead 25 leads from the armature 16 to a terminal 26 which is preferably adjustable for purposes of installation and manufacture, but which is stationary once the device has been set into operation. The terminal 26 establishes electrical contact with one end of the resistance 24, and a number of leads 2? extend from spaced portions of the resistance 24 to the contacts above referred to as a group. These contacts are arranged in sequence longitudinally along the arm 21 and for illustrative purposes I will point out that the first contact 28, connected with the end of the resistance 24 opposite the terminal 26, is positioned slightly and next above the contact 22; whereas the last contact 29, connected to the resistance 24 at the point nearest the terminal 26, is positioned at the greatest distance from the contact 22.

Within the well I provide a supply of conductive liquid such as the mercury 30, and this supply is just sufficient in quantity so that the level thereof is normally too low to touch and submerge all of the contacts. More particularly, this level is of such a height that normally it submerges only predetermined certain of the contacts. In the illustrated form, the level of the mercury is normally at a point where it submerges the contact 22 to establish electrical connection therewith.

Before describing the other features of my invention, it will be obvious that under normal circumstances the motor will not be running for although one side of the line or current source is electrically connected with the mercury 30, through the contact 22, the other side of the armature is out of contact with the mercury 30. It will also be obvious that a rise in level of the mercury in the arm 21 will successively establish contact with the remaining contacts. That is, a rise in level will initially cause the mercury to touch and submerge the contact 28, and a continued rise willsuccessively establish connection with the remaining contacts, until finally all the contacts, including the last contact 29, will be submerged in the mercury. As the contacts from 28 to 29 are touched by the mercury, the motor will not only start at a slow rate of speed, but will speed up gradually, the rise of mercury cutting out successive portions of the resistance 24. Similarly, when the mercury level falls, successive portions of the resistance 24 will be re inserted in the circuit of the motor and will cause a slowing of the latter.

The manner in which I cause the mercury level to rise and fall is a particular feature of my invention. It is to be noted that the upper ends of the U-shaped well 19 are open to the atmosphere. Although I prefer to provide a cap 31 upon the outer end of the arm 21, nevertheless it is to be noted that a small aperture 32 is provided. This exposure of the Well simplifies the device and allows me to dispense entirely with the use of any gaseous pressures or the like.

Briefly, I achieve the desired rise and fall of the mercury level by a principle of displacement of liquid, a displacement member being so constructed and mounted that it is adapted to enter the mercury in the torus ring 20 of the well, thereby causing the mercury level to rise accordingly in both arms of the well. I have illustratively shown a displacement member 33 which is pivoted at 34, the axis of this pivot being coincident with the center of curvatureof the torus ring previously mentioned. The member 33 carries a head 35 which is arcuate and concentric with the axis of the pivot 34. The head 35 is adapted to swing in an arc within the arm 20. In Figure 2 it has been shown out of contact with the mercury 30, but it is obvious that when the member is swung in a counterclockwise direction, as viewed in this figure, the head 35 will enter the mercury 30 and displace corresponding amounts thereof.

soever, it is a feature of my invention to provide 1 a small mass of non-conductive liquid such as the oil 36 upon the level of the mercury 30 in the arm 21. This oil is unreactive both physically and electrically toward the contacts touched thereby and serves the valuable purpose of quenching any spark which might be induced as the level of mercury advances or recedes. It also prevents oxidation of the mercury.

To render the rheostat device responsive to the operation of the ticker 10, I provide a lever 37 upon the pivot 34, this lever being provided with a finger 38 adapted to rest gravitationally upon the tape 11 as the latter approaches the projecting device 12.

The operation of my apparatus will be apparent from the foregoing description. Under normal circumstances the displacement member 33 is in the position shown in Figure 2 and the motor is not operating. As the ticker commences to discharge marked tape, the finger 38 bears down upon the latter and rests within the loop or festoon which forms between the discharge opening of the ticker 10 and the entrance opening of the projecting device 12. If the rate of discharge of the ticker 10 is not very great, this loop or festoon will not be very deep, and the motor will operate at the slow rate of speed which corresponds to electrical contact established between the contacts 22 and 28. Should the ticker 10 speed up and commence to discharge tape at a greater rate of speed, the loop of tape will increase in depth and the lever 37 will drop to a greater extent. This will cause the head to displace a greater amount of mercury and the level of the latter will accordingly rise to a greater height, successively submerging certain additional contacts in the arm 21. As each contact is submerged, the motor will speed up by a corresponding amount. The resistance 24 is so constructed and arranged with respect to the bores of the well and the size of the displacement member 33 that when the ticker 10 is discharging tape at its maximum rate of speed, the mercury will be submerging all of the contacts in the arm 21 and the motor will operate at a correspondingly rapid rate of speed suflicient to take care of the tape being discharged. Similarly, should the ticker thereafter operate at a slower rate of speed, the advancement of the tape will not cease entirely, but a rise of the lever 37 will lower the level of the mercury by a slight degree and the motor will thereby be caused to operate at a slightly reduced speed. Eventually, when the ticker ceases to operate entirely, the pull upon the tape will cause 'the lever 37 to rise into the normal position of Figure 2, at which time electrical connection to the motor will be entirely discontinued.

The extreme simplicity of my construction will be apparent to those skilled in the art. The only moving part is thedisplacement member 33, and since this is pivoted, as at 34, no difficulty whatsoever is encountered in properly mounting the same and in keeping the same properly lubricated and smoothly operating. No parts of my construction need be replaced since there is nothing to wear out. Furthermore, my construction operates entirely noiselessly and requires no attention whatsoever.

It will also be understood that certain phases of my invention, particularly with respect to the automatic switch, are not limited to employment with projecting machines of the character illustrated, and with respect to such features of my invention I do not mean to limit myself to the specific use herein illustrated and described.

In general, it will be 'obvious that changes in the details herein described and illustrated and described for the purpose of explaining the nature of my invention may be made by those skilled in the art without departing from the spirit and scope of the invention as expressed in the appended claims. It is therefore intended that these details be interpreted as illustrative and not in a limiting sense. I

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is 1. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a tape pulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic rheostat device for controlling the speed of said motor, said device comprising a well, a set of rheostat contacts projecting thereinto, a supply of conductive liquid in the well and normally at a level too low to submerge all of said contacts, a movable displacement member adapted to enter said liquid to raise the level thereof accordingly, and means responsive to the rate of ticker discharge for moving said member.

2. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a

tape pulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic rheostat device for controlling the speed of said motor, said device comprising a well, a set of rheostat contacts projecting thereinto, a supply of conductive liquid in the well and normally at a level too low to submerge all of said contacts, a movable displacement member adapted to enter said liquid to raise the level thereof accordingly, and means responsive to the rate of ticker discharge for moving said member; said last named means comprising a lever associated with said member and provided with a finger adapted gravitationally to bear on the tape approaching said light aperture.

3. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a tape pulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic device for controlling the speed of said motor, said device comprising a rheostat, a mercury well, a set of contacts electrically connected to said rheostat and projecting at spaced points into saidwell, the mercury being normally at a level too low to touch any of said contacts, whereby the motor stops, said contacts being so arranged that successive submersion in the mercury starts and speeds up the motor accordingly, a movable displacement member mounted for movement into and out of the mercury to raise and lower the level accordingly, and means responsive to the rate of ticker discharge for moving said member.

4. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a tape pulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic rheostat device for controlling the speed of said motor responsively to the rate of tape discharge, said device including a stationary well with contacts therein electrically connected with said motor, a supply of conductive liquid in said well normally at a level too low to submerge all contacts, and a' movable displacement member adapted to enter said liquid to raise the level thereof accordingly and cause successive submersion of said contacts.

5. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a tape pulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic rheostat device for controlling the speed of said motor responsively to the rate of tape discharge, said device including a stationary U-shaped well with a set of spaced contacts in one arm thereof and electrically controlling the operation of said motor, a supply of conductive liquid in said well normally at a level too low to submerge all contacts, a movable displacement member adapted to enter the liquid in the other arm to raise the level and cause successive submersion of contacts accordingly, and means responsive to the rate of tape discharge for moving said member.

6. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a tape pulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic rheostat device for controlling the speed of said motor responsively to the rate of tape discharge, said device including a stationary U-shaped Well with a set of spaced contacts in one arm thereof and electrically controlling the operation of said motor, the other arm conforming to a torus ring, a supply of conductive liquid in said well normally at a level too low to submerge more than certain predetermined contacts, and an arcuate displacement member pivotally mounted at the center of curvature of said torus ring for entering the liquid in said torus-ring arm to raise the level of the liquid accordingly and cause successive predetermined submersion of additional contacts.

'7. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a tapepulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic rheostat device for controlling the speed of said motor responsively to the rate of tape discharge, said device including a stationary U-shaped-well with a set of spaced contacts in one arm thereof and electrically controlling the operation of said motor, the other arm conforming to a torus ring, a supply of conductive liquid in said well normally at a level too low to submerge more than certain predetermined contacts, a displacement member pivoted at the center of curvature of said torus ring and provided With a head conforming to a concentric torus portion, said head being movable into and out of the liquid in said torus-ring arm to raise the level accordingly and bring predetermined other contacts into submersion, and means responsive to the rate of tape discharge for pivoting said displacement member.

8. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a tape pulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic rheostat device for controlling the speed of said motor, said device comprising a well, a set of rheostat contacts projecting thereinto, a supply of conductive liquid in the well and normally not submerging all of said contacts, a movable member adapted to actuate said liquid to establish an electric circuit through any of said rheostat contacts according to the rate of tape discharge, and

- means responsive to the rate of tape discharge tacts projecting thereinto, a supply of conductive liquid in the well and normally not submerging all of said contacts, a movable member adapted to actuate said liquid to establish an electric circuit through any of said rheostat contacts according to the rate of tape discharge, and means responsive to the rate oftape discharge for moving said member, said last named means comprising a lever associated with said member and provided with a finger engaging the tape approaching said light aperture and responsive to deflections therein. I

10. In a stock ticker projecting machine adapted to discharge marked tape at varying rates, a tape pulling mechanism including an electric motor for drawing the tape across the light aperture of the projecting machine, an automatic rheostat device for controlling the speed of said motor, said device comprising a well, a set of rheostat contacts projecting into said well, a supply of conductive liquid in the well and normally not submerging all of said contacts, and a device responsive to the rate of tape discharge to the light aperture for actuating said liquid to establish an electric circuit through any of said rheostat contacts according to the rate of tape discharge.

11. The combination with a stock ticker tape, of a tape pulling device for drawing the tape across the light aperture of a projector, a device for controlling the speed of operation of said tape pulling device according to the rate at which the tape is supplied to the light aperture consisting of a rheostat having a plurality of contacts, a mercury bath, a plunger for causing said mercury to cut in the successive resistances of said rheostat to facilitate a gradual start from a period of rest and a gradual arrest of the tape, and means sensitive to the slack in the tape at the entrance to the light aperture operatively connected to said plunger to actuate said plunger.

12. The combination with a stock ticker tape, of a tape puller for pulling the tape across the light aperture of a projecting machine as it is delivered thereto, a tape feed for feeding the tape to the light aperture, the tape puller and tape feed cooperating to form slack at the entrance to the light aperture when the tape feed operates and to take up the slack so formed when the tape feed comes to rest, an electric motor operatively connected for driving said tape puller, a rheostat for controlling the speed of operation of the motor and consequently of the tape puller, a mercury bath, a plunger for causing the mercury in said bath to cut in the successive resistances of said rheostat as the plunger rises to facilitate a gradual start from a period of rest and a gradual arrest of the tape, and an arm resting on the tape at the entrance to said light aperture and operatively connected to said plunger to actuate the same.

13. The combination with a stock ticker tape,

entrance to the light aperture when the tape feed 1 operates and to take up the slack so formed when the tape feed comes to rest, and electric motor operatively connected for driving said tape puller, a rheostat for controlling the speed of operation of the motor and consequently of the tape puller, there being an upwardly inclined chamber, the successive contacts of the rheostat communicating with said chamber, a mercury bath, a plunger causing the mercury in said bath to move upwardly into said chamber to cut out the successive resistances of the rheostat as the mercury rises and consequently as the plunger descends to facilitate a gradual start from a period of rest and a gradual arrest of the tape, and an arm resting on the tape at the entrance end to said light aperture and operatively connected to said plunger to cause said plunger to descend when slack is formed in said tape.

14. The combination with a stock ticker tape, of a tape feed, a tape puller for pulling the tape through the projecting machine as it is delivered by the tape feed, the tape puller and tape feed cooperating to form slack at the entrance end to the light aperture when the tape feed operates and to take up the slack so formed when the tape feed comes to rest, an electric motor operatively connected for driving said tape puller, a rheostat for controlling the speed of operation of the motor and consequently of the tape puller, there being an upwardly inclined chamber, the successive contacts of the rheostat communicating with said chamber, a mercury bath, a plunger causing the mercury in said bath to move upwardly into said chamber to cut out the successive resistances of the rheostat as the mercury rises and consequently as the plunger descends to facilitate a gradual start from a period of rest and a gradual arrest of the tape, an arm resting on the tape at the entrance end to said light aperture and operatively connected to said plunger to cause said plunger to descend when slack is formed in said tape, and a supply of oil on the surface of the mercury in said bath to promptly quench the formation of any sparks when contact is made or broken with said rheostat.

15. The combination with a stock ticker tape, of a tape pulling device for drawing the tape across the light aperture of a projector, a device for controlling the speed of operation of said tape pulling device according to the rate at which the tape is supplied to the light aperture consisting of a rheostat having a plurality of contacts, a well of conductive liquid, a plunger for causing said conductive liquid to cut in the successive resistances of said rheostat, and means responsive to deflections in the tape at the entrance to the light aperture operatively connected to said plunger to actuate said plunger.

16. 'The combination with a stock ticker tape, of a tape pulling device for drawing the tape across the light aperture of a projector, a device for controlling the operation of said tape pulling device according to the rate at which the tape is supplied to the light aperture consisting of a rheostat having a plurality of contacts, a well of conductive liquid, a plunger, said well having one passage for receiving said plunger, and a second passage in communication with said contacts, and means responsive to deflections in the tape to actuate said plunger in turn to raise the level of said conductive liquid and thereby cut in the successive resistances of said rheostat according to the magnitudeof the deflection in the tape.

AUGUST D. EITZEN. 

